我正在尝试制作一个类似于 Photoshop 或 Paint Shop Pro 中的图像处理框架,但我遇到了问题。
现在我有一个带有 JDesktopPane 的 JFrame 窗口。当我单击按钮时,会生成一个 JInternalFrame,其中包含以下组件:
imageLabel = new JLabel("picture.png");
scrollPane.setViewPort(imageLabel);
internalFrame.add(scrollPane); // I also tried with a BorderLayout()
desktopPane.add(internalFrame);
我的问题是这样的:如果 JLabel 小于 JInternalFrame,我不希望 JLabel 或 JScrollPane 拉伸(stretch)到 JInternalFrame 的大小。
我尝试用“空”JLabel 填充 JLabel 周围的空间。我尝试过切换 JScrollPane 的布局样式。我尝试将 JLabel 和 JScrollPane 的首选尺寸和最大尺寸设置为 picture.png 的尺寸。这些都不能满足我的需要。我不希望 JLabel 周围的空白“空间”成为 JScrollPane 或 JLabel 的一部分,这样我就可以使用各种 MouseEvents 在图片本身上触发,而不是“拉伸(stretch)”JLabel 或 JScrollPane 留下的空间我调整了 JInternalFrame 的大小。
提前致谢。
Edit1:这里有一些代码突出了这个问题。
import java.awt.*;
import java.awt.event.*;
class fooFrame extends JFrame implements MouseListener
{
private static fooFrame frame;
JLabel fooLabel;
public fooFrame()
{
JDesktopPane background = new JDesktopPane();
JInternalFrame internalFrame = new JInternalFrame("Internal Frame", true, true, true, true);
internalFrame.setSize(500, 500);
internalFrame.setLocation(20, 20);
internalFrame.setVisible(true);
Image image = Toolkit.getDefaultToolkit().getImage("test.gif");
fooLabel = new JLabel(new ImageIcon("test.gif"));
fooLabel.setPreferredSize(new Dimension(image.getWidth(null), image.getHeight(null)));
JScrollPane fooScrollPane = new JScrollPane(fooLabel, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
fooScrollPane.setPreferredSize(new Dimension(fooLabel.getWidth(), fooLabel.getHeight()));
fooScrollPane.setViewportView(fooLabel); // add JLabel to JScrollPane
internalFrame.add(fooScrollPane); // add JScrollPane to JInternalFrame
background.add(internalFrame); // add JInternalFrame to JDesktopPanel
this.setContentPane(background); // add JDesktopPanel to JFrame
fooLabel.addMouseListener(this);
}
public void mouseClicked(MouseEvent me)
{
if (me.getSource() == fooLabel)
System.out.println("Clicked the picture.");
}
public void mouseEntered(MouseEvent me)
{
if (me.getSource() == fooLabel)
System.out.println("Entered the picture.");
}
public void mouseExited(MouseEvent me)
{
if (me.getSource() == fooLabel)
System.out.println("Exited the picture.");
}
public void mousePressed(MouseEvent me){}
public void mouseReleased(MouseEvent me){}
public static void createAndShowGUI()
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch (Exception e) { }
frame = new fooFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("foo");
frame.setSize(800,600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
您必须获得自己的“test.gif”,如果您使internalFrame大于图片,它将用标签填充剩余空间。因为当我穿过内部框架时,所有鼠标事件都会触发,而不是像我希望的那样在图片上发生。
Edit2:根据 Kleopatra 的建议修改了代码。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.LineBorder;
public class a1
{
public static void main(String[] args)
{
fooFrame.createAndShowGUI();
}
}
class fooFrame extends JFrame implements MouseListener
{
private static fooFrame frame;
JLabel fooLabel;
public fooFrame()
{
JDesktopPane background = new JDesktopPane();
JInternalFrame internalFrame = new JInternalFrame("Internal Frame", true, true, true, true);
internalFrame.setLocation(20, 20);
internalFrame.setVisible(true);
internalFrame.pack();
Image image = Toolkit.getDefaultToolkit().getImage("test.gif");
fooLabel = new JLabel(new ImageIcon(image));
fooLabel.setBorder(new LineBorder(Color.PINK));
JScrollPane fooScrollPane = new JScrollPane((fooLabel), JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
internalFrame.setLayout(new BoxLayout(internalFrame.getContentPane(), BoxLayout.LINE_AXIS));
fooScrollPane.setViewportView(fooLabel); // add JLabel to JScrollPane
internalFrame.add(fooScrollPane); // add JScrollPane to JInternalFrame
background.add(internalFrame); // add JInternalFrame to JDesktopPanel
this.setContentPane(background); // add JDesktopPanel to JFrame
fooLabel.addMouseListener(this);
}
public void mouseClicked(MouseEvent me)
{
if (me.getSource() == fooLabel)
System.out.println("Clicked the picture.");
}
public void mouseEntered(MouseEvent me)
{
if (me.getSource() == fooLabel)
System.out.println("Entered the picture.");
}
public void mouseExited(MouseEvent me)
{
if (me.getSource() == fooLabel)
System.out.println("Exited the picture.");
}
public void mousePressed(MouseEvent me)
{
}
public void mouseReleased(MouseEvent me)
{
}
@Override
public Dimension getMaximumSize()
{
return getPreferredSize();
}
public static void createAndShowGUI()
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e)
{
}
frame = new fooFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("foo");
frame.setSize(800, 600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
最佳答案
在此示例中,内部帧最初不超过 MAX_SIZE
像素。较小的图片将调整大小,以便不需要滚动。
附录:仔细阅读标题,您可能还想限制内部框架的最大大小:
internalFrame.setMaximumSize(new Dimension(fooLabel.getPreferredSize()));
附录:这种变化可能有助于澄清问题。使用默认布局 BorderLayout.CENTER
时,滚动条会按要求显示,但 MouseListener
的行为不会按预期进行。使用尊重首选尺寸的布局,FlowLayout
,MouseListener
可以正确报告,但滚动条永远不会出现,因为标签的首选尺寸永远不会改变。为了方便起见,我添加了合成图像。
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
class PictureFrame extends JFrame {
private static final String NAME = "image.jpg";
public PictureFrame() {
JDesktopPane dtp = new JDesktopPane();
dtp.add(new MyFrame("Large", FauxImage.create(300, 500), 50));
dtp.add(new MyFrame("Small", FauxImage.create(200, 200), 25));
this.add(dtp);
}
private static class MyFrame extends JInternalFrame {
private static final int MAX_SIZE = 256;
public MyFrame(String title, Image image, int offset) {
super(title, true, true, true, true);
//this.setLayout(new FlowLayout());
final JLabel label = new JLabel(new ImageIcon(image));
this.add(new JScrollPane(label));
this.pack();
int w = Math.min(MAX_SIZE, image.getWidth(null));
int h = Math.min(MAX_SIZE, image.getHeight(null));
Insets i = this.getInsets();
this.setSize(w + i.left + i.right, h + i.top + i.bottom);
this.setLocation(offset, offset);
this.setVisible(true);
label.addMouseListener(new MouseAdapter() {
@Override
public void mouseEntered(MouseEvent me) {
if (me.getSource() == label) {
System.out.println("Entered.");
}
}
@Override
public void mouseExited(MouseEvent me) {
if (me.getSource() == label) {
System.out.println("Exited.");
}
}
});
}
}
private static class FauxImage {
static public Image create(int w, int h) {
BufferedImage bi = new BufferedImage(
w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = bi.createGraphics();
g2d.setPaint(Color.lightGray);
g2d.fillRect(0, 0, w, h);
g2d.setColor(Color.black);
String s = w + "\u00D7" + h;
int x = (w - g2d.getFontMetrics().stringWidth(s)) / 2;
g2d.drawString(s, x, 24);
g2d.dispose();
return bi;
}
}
public static void createAndShowGUI() {
PictureFrame frame = new PictureFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("PictureFrame");
frame.setSize(640, 400);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
createAndShowGUI();
}
});
}
}
关于java - 当 setMaximumSize() 和 setPreferedSize() 不起作用时,如何对 JComponent 设置硬限制?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8088885/